A filter, a concentrator, or both, is often used in conjunction with sampling, analysis, and detection devices. The filter is used to prevent certain particulates (e.g., those out of a size range of interest, those likely to cause mechanical problems, etc.) from reaching analysis or detection equipment. The concentrator is used to increase the concentration of particles in a volume of gas (e.g., air, etc.).
FIG. 1 depicts conventional conditioning system 100 being used in conjunction with detector 114. In this example, the purpose of detector 114 is to monitor the air for particles within a certain size range, such as between 1 to 10 microns. The function of conditioning system 100 is to deliver particles within the size range of interest, and at a concentrated level, to detector 114 and to prevent particles that are larger than the size range of interest from reaching concentrator 104 or detector 114. The air-flow through system 100 is depicted by the arrows.
Conditioning system 100 includes filter 102, concentrator 104, and pumps 110 and 112. Filter 102 traps relatively large particles (i.e., greater than about 15 microns in this example) to prevent them from reaching concentrator 104 and/or detector 114. Pumps 110 and 112 are used for drawing air through filter 102, concentrator 104, and detector 112. In particular, for the system depicted in FIG. 1, pump 110 is used to draw air through port 106 and pump 112 is used to draw air through port 108 toward detector 114. Particles that are smaller than the size range of interest are drawn through port 106. Particles within the size range of interest are drawn through port 108.
Filter 102 and concentrator 104 typically include surfaces that tend to clog, especially when the filter or concentrator are used in dirty environments, such as underground passages or tunnels, etc. Frequent maintenance is therefore required to maintain the performance of these conditioning-system elements. This drives up the operational cost of devices that use a conditioning system, such as detector 114.
This problem of clogging has been addressed in the prior art by using replaceable mesh-filtration systems. But these filters must be replaced when they clog, which occurs frequently in dirty environments.
As a consequence, there is a need for device or system for addressing the clogging problem in filters and concentrators.